Varying thickness Helmet for reduced weight and increased protection

ABSTRACT

A helmet in which the material thickness is optimized to utilize multiple defeat mechanisms against a range of threats and to provide varying levels of protection in different areas based on the expected distribution and orientation of threats. Threat types as well as likely threat locations are both used to determine optimal material types and thickness at different points on the helmet to provide the user with the greatest overall level of personal protection possible with a helmet of a given maximum weight.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention generally relates to personal protection equipment. Specifically, the invention relates to a helmet device that provides users with maximum levels of personal protection and minimum weight. This is accomplished by structuring the material properties of the helmet to focus protection in helmet areas more likely to be successfully attacked based on reasonable practice and threat models.

With the ongoing conflicts in Iraq and Afghanistan, the role of personal protection equipment is more critical than ever. In practice helmets are a compromise between the level of protection afforded to the soldier and the weight burden the soldier must carry on their head.

Past efforts have related to the material construction of the helmet, the overall coverage area of the helmet, and the helmet fabrication process. These efforts have sought to increase the helmet's ability to defeat particular threats, and to increase producibility and affordability. The resulting helmets have included the M-1 Steel Helmet, the Personnel Armor System for Ground Troops (PASGT) and the Advanced Combat Helmet (ACH) fielded by the US Army. No previous efforts have sought to optimize the construction of a helmet to the combination of a particular threat type, modeled three dimensional threat distribution, helmet defeat mechanism(s), and overall weight.

Accordingly, several objects and advantages of the invention are:

(a) to provide a helmet construction that can utilize multiple projectile defeat mechanisms including deflection and others;

(b) to provide a helmet construction that can be optimized to the types of threats anticipated;

(c) to provide a helmet construction that can be optimized to the three dimensional distribution of directions and locations from which threats are likely to deployed against the helmet user;

(c) to provide a helmet constructed to stop certain threats, and to cause to skip other threats that cannot be easily stopped.

(d) to provide a construction which effectively presents an enemy with a smaller “kill-zone” for a particular weapon by reducing the projected area the incoming round must hit to defeat the helmet.

In accordance with the present invention the Varying Thickness Helmet for Reduced Weight and Increased is an article of protective equipment designed to offer improved protection from small-arms fire and fragmentation without the generally corresponding system weight. This optimized thickness makes use of two specific defeat mechanisms that can be achieved with composite and metallic structures, specifically, in a successful piece of personal protective equipment, bullets can either be stopped or deflected. The construction of the helmet makes use of these two defeat mechanisms in different ways in different areas of the helmet. The non-uniform spatial distribution of helmet properties, and incoming threat defeat mechanism is based on reasonable practice, a three dimensional model of likely threat locations, the threat type, and target location.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of the Varying Thickness Helmet.

FIG. 2 shows a front section view of the Varying Thickness Helmet.

FIG. 3 shows an example vertical threat distribution.

FIG. 4 shows an example horizontal threat distribution.

DETAILED DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the Varying Thickness Helmet is illustrated in FIG. 1 (angled view), and FIG. 2 (front section view). FIG. 1 shows a perspective view of the invention. The Varying Thickness Helmet inner surface 1 is a smooth surface sized to fit the head of a nominal user. It is expected that the helmet would be offered in a range of sizes to accommodate a range of users. The sizing of the Varying Thickness Helmet allows for the use of a suspension system comprised of foam, webbing, or other between the helmet and the user's head. The Varying Thickness Helmet outer surface 2 is a smooth surface spaced a non-uniform distance from the inner surface. This non-uniform spacing results in a helmet in which the material thickness varies at different points along the surface of the helmet.

FIG. 1 also shows mounting points 3 for devices including night vision equipment, thermal imaging equipment, acoustic and other sensors, and communication equipment. The suspension system 4 includes a chin strap and foam pads or webbing which retain the helmet to the user's head in the event of a blunt impact, ballistic, or blast event. Furthermore, the foam pads or webbing provide shock isolation between the helmet shell and the user's head which will mitigate shock associated with blunt impact, ballistic, and blast events.

FIG. 2 shows a front section view of the invention. In this view, the inner 1 and outer 2 surfaces are clearly evident. Additionally, it can be seen that the two surfaces are separated by a distance that varies along the profile of the helmet. This varying thickness is optimized to provide operators protection from threats as a function of the threat type, threat distance, and the location from which the threat is fired at the target.

FIG. 3 shows an example vertical threat distribution, with example low threat areas 5, example medium threat areas 6, and example high threat areas 7 illustrated. FIG. 4 shows an example horizontal threat distribution with example low threat areas 5, example medium threat areas 6, and example high threat areas 7 illustrated

The helmet may be manufactured from metal (Ti, RHA Steel, HH Steel, or other), a composite material (Kevlar, Dyneema, Spectra, Twaron, or other), ceramic, or any combination of these materials. The thickness of the helmet itself is an optimized function of using different defeat mechanisms to address different threats in different ways. In areas in which a soldier performing a specific mission is unlikely to be targeted, the material thickness is lower, and may be sized only to provide protection from small fragmentation, incidental impact, or low velocity/low energy small arms fire. Areas that fall in this category may include, but are not limited to the helmet's crown, brim, side, rear, and front. Specifically, threats may be oriented in any direction; different directions are more likely than others, and different threats are more or less likely to target specific areas. Based on general practice, and a three-dimensional model of threat orientation and likelihood, the thickness of the helmet is varied across the entire surface. In areas in which a soldier is likely to take a direct hit, the thickness of the helmet is determined by a requirement to stop likely incoming projectiles. For larger projectiles, and Armor-Piercing projectiles with high enough energy that complete direct protection from a head-borne system is not feasible, the thickness is sized such as to induce a glancing behavior in the incoming projectile from a range of likely shot angles. This glancing behavior may include situations in which the incoming projectile is seen to skip off of the surface, as well as situations in which the incoming projectile tumbles off of the surface.

It should be recognized that the material requirements (composition, thickness, and geometry) required to either stop an incoming projectile, or induce a glancing behavior from a range of incoming projectile angles, are very different. Consequently, a helmet sized and shaped to benefit from both of these defeat mechanisms may be constructed and optimized to reduce the overall weight borne by the user, while providing an overall level of protection not possible for a given weight without using this technique.

An example of the benefit of this type of helmet to a user will be seen,in a situation in which a user is being targeted in a rural setting. In this setting, the threat orientation may be likely to come from a sector located at or near ground level, and within an arc of 90° across the front of the helmet. In this instance, the helmet would be constructed with reduced thickness in low threat areas such as the top and rear of the helmet, thereby reducing the overall weight of the helmet. In the higher threat area, the helmet thickness and construction will be modified to defeat the expected threat round. The defeat mechanism may be different based on different threat types. As an example, a 7.62×39 mm PS Ball round may be stopped directly, while a 7.62×54 mm AP round may be deflected. In the deflection case, the effect is that the shooter will have to hit a significantly smaller target in order to avoid being defeated by deflection off of the helmet. In a specific instance, this may be analogous to a requirement that a particular shooter aiming from 500 meters, may have to shoot with the same accuracy that would be required at 700 meters in order to achieve their desired effect. As the probability of an accurate hit at 700 meters is substantially lower than at 500 meters, the helmet user's survivability percentage will be significantly increased.

Operation

In operation, the Varying Thickness Helmet for Minimum Weight and Maximum Protection is worn by an operator in the same manner that a standard helmet would be worn. The Varying Thickness Helmet for Minimum Weight and Maximum Protection will be affixed to the user's head using the same range of attachment options used with standard helmets. Furthermore, the Varying Thickness Helmet for Minimum Weight and Maximum Protection will incorporate the same type of interior suspension system common in ordinary helmets.

Scope of Invention

The reader will see a helmet in which the material thickness and type are optimized to utilize multiple defeat mechanisms against a range of threats and threat orientations. Threat types as well as likely threat locations are used to determine optimal material types and thickness at different points across the entire surface of the helmet to provide the user with the greatest overall level of personal protection possible with a helmet of a given maximum weight. This feature can provide alternatively a higher level of protection at a given overall helmet weight, or an equivalent overall level of protection at a helmet of reduced overall weight. 

1. A helmet comprising a shell having at least side, front, and top sectors. The thickness and composition of each sector defined to provide protection appropriate to the most likely threat at that specific region. a. Said shell to be comprised of metal, ceramic, or composite. i. Said shell to include metal thickness ranging up to 0.5 inches. ii. Said shell to include ceramic thicknesses ranging up to 0.5 inches. iii. Said shell to include composite thicknesses ranging up to 1.25 inches. b. Said shell to be configured to have a stand-off distance between the inner surface and the user's head sufficient to allow required back-face deformation associated with normal operation, as well as the use of a suspension system to absorb shock resulting from ballistic and blunt impacts. Said stand-off distance to be between 0.125 inches and 2.0 inches. i. Said shell to further incorporate attachment points for devices including but not limited to night vision equipment, thermal imaging equipment, acoustic and other sensors, and communication equipment. c. A suspension comprised of components to include a chin strap, and foam pads or webbing. i. Said chin strap to retain the helmet to the user's head during normal use, as well as in the event of a blunt impact, ballistic or blast event. ii. Said foam pads or webbing to provide shock isolation between the helmet shell and the user's head, which will mitigate transmitted shock associated with blunt impact, ballistic, and blast events.
 2. A method of making a helmet for an individual's head having distinct sectors which stop select fragmentation, stop select ballistic threats, and deflect other threats and fragments. The thickness, composition, and construction of each sector configured to provide protection appropriate to the most likely threat at that specific region, thereby reducing the weight carried on a user's head, and increasing the provided protection from likely events. a. Weight is reduced by tailoring the local thickness of the helmet material to the threats expected at each given region. b. Protection is increased by providing increased thickness in areas having a higher probability of being exposed to more severe threats. 